Power operated typewriter with interlock means

ABSTRACT

An interlocking apparatus for power operated typewriters to prevent depression of more than one key lever simultaneously comprises a number of balls located under the array of key levers and bellcrank levers corresponding to each key lever and pivotable about a fixed axis from an inoperative position to an operative position in which the lever is engaged with said balls. The lever is pivoted into the operative position by a trigger in the type actuating mechanism upon depression of the key lever and is pivoted back to the inoperative position by a reciprocating member in said type actuating mechanism after the initiation of the reciprocating movement of the member.

United States Patent Hishida et al.

[ 1 Feb. 15,1972

[54] POWER OPERATED TYPEWRITER WITH INTERLOCK MEANS [72] Inventors: Yukio Hishida; Takami Kato; Takashi Hirata; Hisao Kurachi, all of Nagoya,

[21] App1.No.: 807,354

3,037,606 6/1962 Blain et a1 ..197/107 X 3,086,635 4/1963 Palmer ..197/107 X 3,191,740 6/1965 Smusz et al. ..197/107 X Primary Examiner-Edgar S. Burr Att0rney-Sughrue, Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT An interlocking apparatus for power operated typewriters to prevent depression of more than one key lever simultaneously comprises a number of balls located under the array of key levers and bellcrank levers corresponding to each key lever and pivotable about a fixed axis from an inoperative position to an operative position in which the lever is engaged with said balls. The lever is pivoted into the operative position by a trigger in the type actuating mechanism upon depression of the key lever and is pivoted back to the inoperative position by a reciprocating member in said type actuating mechanism after the initiation of the reciprocating movement of the member.

7 Claims, 5 Drawing Figures PAIENTEDFEa 5 4912 FIG] SHEET 1 0F 5 INVENTORS YUKIO HISHIDA TAKAHI KATO TAKASHI HIRATA HISAO KURACHI PATENTEU FE! I 5 I972 SHEET 2 BF 5 mvzmoas YUKIO HISHIDA u we SHIYHIRATA HISAO KURACHI PAIENTEI] F [B I 5 I972 SHEET 3 0F 5 INVENTORS YUKIO HISHIDA TAKAMI KATO TAKASHI HIRATA HISAO KURACHI PATENTEDFEB 15 I972 SHEEI h 0F 5 INVEN YUKIO HI TAKAII KATO 'MKASHI HIRATA HISAO KURACHI PATENTEDFEB 15 I972 sum 5 0F 5 m; llllllllh w c, a

INVENTORS YUKIO HISHIDA TAKAMI KATO TAKASHI HIRATA HISAO KURACHI POWER OPERATED TYPEWRITER WITH INTERLOCK MEANS FIELD OF THE INVENTION The present invention relates to an interlocking device for preventing simultaneous depression of the' key levers in order to prevent jamming of the type bars in a power operated typewriter.

DESCRIPTION OF PRIOR ART Heretofore, a construction has been known wherein balls or rollers are arranged under the key levers as a locking device for preventing the simultaneous depression of the key levers. However, in the conventional device, key levers other than that advanced are prevented from being depressed by the arrangement of the balls or rollers. This presents a problem in that unless the depressed key lever is completely disengaged from the arrangement of the balls or the like, the next key lever cannot be depressed and normal smooth typing operation cannot be obtained, because of the construction wherein the key lever is directly engaged with the balls or rollers, In the U.S. Pat. No. 2,870,896 (inventor: Heinrich Riffel) an improvement of the above-described device is disclosed. The device disclosed in the patent has a slide lever which is supported by the key lever and movable slightly relative thereto, and which is engaged with the balls or rollers in response to the depression of the key lever. In this construction, the slide lever engaged with the balls or rollers is moved independently from and in relation to the key lever and is disengaged from the balls or rollers by the movement of the type actuating mechanism at the initial step of the movement before the return of the key lever to the original position thereof.

In this construction, a disadvantage lies in that the structure of the connecting portion of the key lever with the slide lever is complicated and the action of the interlocking mechanism is not fully corresponding to the typing action at high speed. Moreover, in this type of construction, when one key lever is depressed at the moment the motor is stopped or the power roll is not rotating, the pawl is removed from the latching condition and is brought into engagement with the roll. By depressing the other key levers one by one, a number of pawls are brought into engagement with the rolls. As a result, when the motor is again started, the motor may be overheated due to the overload caused by the number of pawls engaged with the rolls. Therefore, in this construction, a particular locking device for preventing the key lever from being depressed at the moment the motor is stopped is required.

SUMMARY OF THE INVENTION The present invention provides a simultaneous double depression preventing device of key levers for preventing more than one key lever from being depressed simultaneously to preventjamming ofthe type bars.

The present invention further provides a simultaneous double depression preventing device of key levers which can be easily produced at a low cost because of the simple construction thereto.

The present invention provides a simultaneous double depression preventing device of key levers which is constructed into a unit to be fixed in the power operated typewriter of the conventional type.

The interlocking device prevents more than one key lever from being depressed at the moment the motor is stopped to protect the motor from overload upon restarting.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional side view of the embodiment in the stationary condition illustrating one set of type action, and

FIGS. 2 through 5 are enlarged explanatory views of the main part of the embodiment shown in FIG. 1 in the operating condition.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring to the drawings showing one type action, the driving power of the type action is given by the toothed snatch roll 10. The roll 10 is provided with a plurality of teeth on the periphery thereof and is driven by a motor and is rotated in the counterclockwise direction continuously as seen in the drawing. A type bar 11 is disposed opposite to the platen 12. The type bar 11 is rotatably mounted to a type bar segment 13 and is normally settled in the normal rest position where it is engaged with the type bar rest 14. The type bar 11 is adapted to move from the rest position and strike at the typing point on the platen 12. An operating member 15 is pivoted at one end thereof to a bellcrank 17 pivotally mounted to a lateral frame 16 and is pivoted at the other end thereof to a link 19 pivotally mounted to a lateral frame 33. The operating member 15 thus forms a four-joint link mechanism together with the bell crank l7 and link 19 which is movable horizontally in a plane which is perpendicular to the roll 10. The operating member 15 is normally held in the rest position shown in FIG. 1 by means of the spring 20. A link 21 is connected to one end of the bellcrank 17 and to the lower end of type bar 11.

An intermediate means for transmitting the power of the roll 10 to the operating member 15 includes an engaging pawl 22 and a holding lever 23. The engaging pawl 22 and holding lever 23 are pivotally mounted to the operating member 15. A spring 24 tensioned between the engaging pawl 22 and holding lever 23 urges the engaging pawl 22 in the clockwise direction and the holding lever 23 is urged in the counterclockwise direction as seen in the drawings. The holding lever 23 is normally positioned at the original position relative to the operating member 15 as shown in FIG. 1, wherein the engaging pawl 22 is held in the disengaged position against the force of the spring 24 where it is prevented from being engaged with the roll 10. The holding lever 23 releases the engaging pawl 22 when the end portion 23 of the holding lever is depressed, thus allowing the projected nose 22a of the pawl 22 to be brought into the position where it is engaged with the roll 10.

A key lever 25 is pivoted at an end thereof to a shaft 26 fixed in the lateral frame 16 and is provided with a key 27 at the other end thereof. The key lever 25 is normally urged to the normal position by a comb spring 28. At the normal position of the key lever 25, the arm 25a extending downward from the central portion of the key lever 25 is engaged with the lateral frame 29.

A positioning device 30 for determining the depressed position of the key lever 25 is provided at the lateral frame 29 in the well-known manner. By the positioning device 30 the key lever 25 is positioned to the first position for single operation and to the second position deeper than the first position for repeating operation. When the key lever 25 is depressed to the first position, a single type action of the type bar 11 is made, and when the key lever 25 is depressed to the second position, the repeated type actions of the type bar 11 are made. While the key lever 25 is held in the second position, the type action is repeated. The repeating action is the same as that of the conventional typewriter, and therefore, the detailed description is omitted.

An operating arm 31 is pivotally mounted to the central portion of the key lever 25, and is normally held at the original position for the key lever as shown in FIG. 1 by the stop 31a against the force of the spring 32. The arm 31 is provided at the lower portion thereof with an engaging ear 31b which is positioned laterally thereto. The engaging ear 31b is located above one end of the holding lever 23.

The simultaneous double depression preventing device of the key lever 25 will now be described. On the lateral frame 33, a groove 33a extending in the longitudinal direction is formed and in the groove 33a a plurality of locking balls 34 in a line shape are arranged. The opposite ends of the groove 33a are closed by the side frame plates (not shown) so that the balls 34 are prevented from getting out of the groove 33a. A

bellcrank lever 35 is formed into an L shape and is inserted into a guiding groove 33b formed with equal intervals in the direction perpendicular to the longitudinal direction of the lateral frame 33, and is pivotally mounted to the fixed shaft 36 fixed to the lateral frame 33. The lever 35 is rotatable between the inoperative position shown in FIG. 1 where the lever 35 is not engaged with the balls and the operative position where the lever 35 is engaged with the balls. The space made in the longitudinal direction when the balls 34 are all put aside is substantially equal to the thickness of a lever 35, so that another lever 35 is prevented from being inserted into the ball arrangement when one of the levers 35 is engaged with the balls 34. A comb spring 37, formed in a curved shape, is attached to the lower portion of the lateral frame 33 and engages one arm of the lever 35 so as to normally hold the lever 35 at the inoperative position where it is not engaged with the ball, as shown in FIG. 1. When the lever 35 is rotated in the counterclockwise direction and one of the arms thereof is passed over the top point of the curve shape of the comb spring 37, the comb spring 37 operates to act on the lever 35 in a direction that is opposite to the inoperative position.

On the other arm of the lever 35 are provided a first engaging ear 35a anda second engaging ear 35b bent in the lateral direction. The first engaging ear 35a is positioned under a projected portion 23b extending downward from the end portion 23a of the holding lever 23 so that the first engaging ear 35a is able to be engaged with the projected portion 23b when the holding lever 23 is rotated in the clockwise direction in the drawing. The second engaging ear 35b is positioned outside of the moving path of the protruding portion 15a formed on the operating member 15 when the lever 35 is in its inoperative position, and is brought into the moving path ofthe protruding portion 150 when the lever 35 is positioned in the operative position. A disengaging screw 38 is screwed into the frame 39 for forcibly disengaging the engaging pawl 22 from the roll 10.

Now the operation of the embodiment of the device in accordance with the present invention as described hereinabove will be described. Initially, the motor is energized and the snatch roll is continuously rotated. The key 27 is depressed so that the key lever 25 is moved from the rest position shown in FIG. 1 to the first position shown in FIG. 2 against the force of the spring 28. By depressing the key lever 25, the operating arm 31 is moved downward so that the engaging ear 31!) thereof is engaged with the end portion 23a of the holding lever 23. By this engagement, the holding lever 23 is rotated in the clockwise direction from the original position relative to the operating member so as to release the engaging pawl 22. The released engaging pawl 22 is quickly rotated in the clockwise direction by the spring 24 so that the projected nose 22a is brought into the rotating range of the roll 10. By bringing the projected nose 22a into the rotating range of the roll 10, the engaging pawl 22 is engaged with the roll 10, and by the power of the driving motor, the operating member 15 is moved leftward against the force of the spring from the rest position. On the releasing operation of the holding lever 23 to release the engaging pawl 22 from its latching position, the projected portion 23b of the holding lever 23 is brought into engagement with the first engaging ear 35a of the lever 35. By the above operation, the bellcrank lever 35 is rotated about the shaft 36 from the inoperative position to the operative position and advanced into the balls 34. During the engagement of lever 35 with the balls 34, the other levers 35 are prevented from being advanced into the balls. Therefore, even if another key lever 35 is attempted to be depressed downward, the full depression downward thereof is prevented and the engaging pawl 22 cannot be released from the latching of the holding lever 23. As described hereinabove, the spring 37 holding the lever 35 in the inoperative position acts to quickly urge the lever 35 to the operative position after the lower end of the arm of the lever 35 moves over the top portion of the spring 37, and to retain the bellcrank lever 35 in the operative position.

Due to the leftward movement of the operating member 15, the protruding portion 15a of the operating member 15 is brought into engagement with the second engaging ear 35b of the bell crank lever 35 positioned in the moving passage so as to push the lever up by a camming action. Accordingly, the lever 35 is rotated in the clockwise direction from the operative position as shown in FIG. 3. As shown in FIG. 4, when the lower end of the arm of the lever 35 is moved over the top portion of the spring 37, the lever 35 is quickly returned to the inoperative position by the spring 37 thus allowing another lever 35 to advance into the balls, thereby enabling another key 27 to be depressed. Since the lever 35 is returned to the inoperative position by the protruding portion 15a of the operating member 15 at the initial step of the movement of the member 15, the depression of another key lever 25 is made possible before the first key lever 25 is completely returned to its rest position.

According to the subsequent movement of the operating member 15, the engaging pawl 22 is engaged with the screw 38, whereby it is forcibly disengaged from the roll 10. As a result, the operating member 15 finishes the forcible transitory driving by the roll 10, but it is further moved leftward by inertia and rotates the bellcrank 17 in the clockwise direction to pull the link 21. During this operation, the type bar 11 makes typing action from the rest position to the typing point on the platen 12. After the type action, the operating member 15 is returned to the rest position by the operation of the spring 20, and the type bar is also returned to the rest position thereof.

The simultaneous double depression preventing device in accordance with the present invention is simple in construction and can be made with low cost. The bellcrank lever 35, fixed shaft 36, locking ball 34 and comb spring 37 forming the device are assembled to the lateral frame 33 beforehand. When assembling the typewriter, the preventing device can be fixed to the typewriter as a unit by fixing the lateral frame 33 to the main typewriter frame. Therefore, assembling and attaching of the device can be extremely easily and quickly completed. When a key 27 is carelessly depressed at the time the, motor is stopped, the engaging pawl 22 corresponding to the key 27 is released from latching of the holding lever 23 and brought into engagement with the roll 10. At the same time, the bellcrank lever 35 is rocked from the inoperative position to the operative position. The bellcrank lever 35 cannot be returned to the inoperative position even if the key 27 is returned to the original position, and is kept in the operative position. Therefore, any other bellcrank lever 35 is prevented from being rocked in the operative position. Accordingly, all of the other key levers 25 are prevented from being depressed and all of the other engaging pawls 22 are prevented from being pivoted in the roll engaging direction. That is, the interlocking device prevents the undesirable pivoting of the number of engaging pawls 22 in the roll engaging direction at the time motor is stopped. Therefore, there is no overloading at the time of starting of the motor and overheating of the motor is thus prevented.

Moreover, though the interlocking device in accordance with the embodiment described hereinabove has been described with respect to the condition wherein the type bar 11 is prevented from jamming, the interlocking device can also be applied to other embodiments such as an interlocking device between the type bar and back space mechanism, carriage return mechanism, and shift mechanism, which are functional mechanisms in a typewriter.

What we claim is:

l. A power operated typewriter comprising:

a frame,

a drive member rotatably supported on said frame,

key levers movably supported on said frame,

type bars pivotably mounted on a type bar segment to strike at a common typing point,

an operating member connected to each of said type bars and mounted on said frame for reciprocating movement in a fixed path,

means for normally holding said operating member in a rest position,

intermediate means carried by said operating member so as to engage with and disengage from said drive member, said intermediate means normally being held in said disengaging condition and adapted to move from said disengaging condition to said engaging condition upon depression of said key lever, thereby to initiate the reciprocating movement of said operating member,

a lateral frame located under said key levers and having a number of guide grooves equally spaced therein,

key locking members mounted on said lateral frame,

a shaft secured to the lateral frame,

a locking lever corresponding to each of said key levers and guided in said guide groove for pivotal movement about said shaft from an inoperative position in which said lever is disengaged from said locking members to an operative position in which said lever is engaged with said locking members, and

spring means mounted on said lateral frame for engaging said locking lever to positively maintain it in said inoperative and operative positions,

said lateral frame, said locking members, said locking lever, said shaft, and said spring means being secured to the frame as a unit,

said intermediate means engaging said locking lever upon depression of said key lever for rocking the locking lever from the inoperative position to the operative position so as to prevent depression of more than one key lever simultaneously,

said locking lever being disposed in the fixed path of movement of said operating member when rocked into the operative position,

said operating member carrying said locking lever out ofthe fixed path and restoring the same to the inoperative position after the initiation of the reciprocating movement thereof.

2. A power operated typewriter comprising:

a frame including a lateral frame,

a power roll rotatably mounted on said frame,

key levers movably supported on said frame,

type bars pivotally mounted on a type bar segment to strike at a common typing point,

an operating member connected to each of said type bars and mounted on said frame for reciprocating movement in a fixed path,

a spring mounted on the frame for normally urging said operating member to a rest position,

intermediate means rockably mounted on the operating member for movement relative to the operating member so as to engage with and disengage from said roll, said intermediate means normally being in said disengaging condition and adapted to rock from said disengaging condition to said engaging condition upon depression of said key lever, thereby initiating the reciprocating movement of said operating member,

key locking members located under said key levers and mounted on said lateral frame,

a fixed shaft secured to the lateral frame,

a bellcrank lever corresponding to each of said key levers and rockable about the fixed shaft from an inoperative position in which one arm of said lever is disengaged from said key locking members to an operative position in which said one arm of said lever is engaged with said key locking members,

said intermediate means engaging another arm of said bellcrank lever upon depression of said key lever for rocking the bellcrank lever from the inoperative position to the operative position soas to prevent depression of more than one key lever simultaneously,

said another arm of the bellcrank lever being disposed in the fixed path of movement of the operating member when said lever is rocked into the operative position,

a leaf spring mounted on said lateral frame for contacting one arm of said bellcrank lever to positively maintain the bellcrank lever in said operative and inoperative positions respectively, and

camming means on said operating member for engaging the locking lever so as to cam said another arm of the bellcrank lever out of said fixed path and restore the' bellcrank lever to the inoperative position after the initiation of the reciprocating movement of the operating member.

3. A power operated typewriter as claimed in claim 2,

wherein said key locking members comprise a plurality of balls located in a groove formed in said lateral frame and arranged in a straight line, and wherein said lateral frame, said bellcrank levers, said balls, said fixed shaft and said leaf spring are secured, as a unit, to the frame.

4. A power operated typewriter comprising:

a frame,

a power roll rotatably mounted on said frame,

type bars pivotally mounted on a type bar segment to strike at a common typing point,

an operating member connected to each of said type bars and mounted on said frame for reciprocating movement in a fixed path,

a spring mounted on the frame for normally urging said operating member to a rest position,

a pawl pivotally mounted on said operating member for rocking movement relative to said operating member to engage with and disengage from said roll,

a holding lever rockably mounted on said operating member for normally locking said pawl in a position disengaged from said roll,

said holding lever being rocked by said key lever to release said pawl upon depression of the key lever,

said operating member being adapted to be moved from said rest position together with said pawl and holding lever by said roll when said pawl is released by the holding lever to engage with said roll, thereby causing one of said type bars to strike toward the typing point,

key locking members located under the key levers and mounted on the frame,

a locking lever corresponding to each of said key levers and rockably mounted on the frame for movement between an inoperative position in which said lever is disengaged from said key locking members and an operative position in which said lever is engaged with said key locking members,

said holding lever engaging the locking lever for rocking the same from the inoperative position to the operative position when the holding lever is rocked upon depression of said key lever,

said locking lever being disposed in the fixed path of movement of the operating member when rocked into the operative position, and

camming means on the operating member for engaging the locking lever so as to move the locking lever out of the fixed path and restore it to the inoperative position after the initiation of the reciprocating movement of the operating member.

5. A power operated typewriter comprising:

a frame,

a power roll rotatably mounted on said frame,

key levers pivotally supported on said frame,

type bars pivotally mounted on a type bar segment to strike at a common typing point, i

an operating member connected to each of said type bars and mounted on said frame for reciprocating movement in a fixed path,

a spring mounted on said frame for normally urging said operating member to its normal rest position,

a pawl rockably mounted on said operating member for rocking movement relative to said operating member to engage with and disengage from said roll,

a holding lever rockably mounted on said operating member for normally locking said pawl in a position disengaged from said roll,

said holding lever being rocked by said key lever to release said pawl upon depression of said key lever,

said operating member being adapted to be moved from said rest position together with said pawl and said holding lever by said roll when said pawl is released by said holding lever to engage with said roll, thereby causing one of said type bars to strike toward said typing point,

a lateral frame located under said key levers and having a number of guide grooves equally spaced therein,

key locking members mounted on said lateral frame,

a fixed shaft secured to the lateral frame,

a bellcrank lever corresponding to each of said key levers and guided in said groove for rocking movement about the fixed shaft from an inoperative position in which one arm of said bellcrank lever is disengaged from said key locking members to an operative position in which one arm of said bellcrank lever is engaged with said key locking members so as to prevent depression of more than one key lever simultaneously,

a spring mounted on said lateral frame for maintaining the bellcrank lever positively in said inoperative and opera tive positions,

said lateral frame, said interlocking members, said bellcrank lever, said shaft and said spring being secured to said frame as a unit,

said holding lever engaging another arm of the bellcrank lever for rocking the bellcrank lever from the inoperative position to the operative position when said holding lever is rocked upon depression of said key lever,

said another arm of said bellcrank lever being disposed in the fixed path of movement of the operating member when rocked into the operative position, and

a projection formed on the operating member for engaging said another arm of the bellcrank lever to move it out of the fixed path and restore the bellcrank lever to the inoperative position after the initiation of the reciprocating movement of the operating member.

6. A power operated typewriter comprising:

a frame,

a power roll rotatably mounted on said frame,

key levers pivotally supported on said frame and depressible from a normal rest position,

type bars pivotally mounted on a type bar segment to strike at a common typing point,

an operating member connected to each of said type bars and mounted on said frame for reciprocating movement in a fixed path,

a spring mounted on said frame for normally urging said operating member to its normal rest position,

a pawl rockably mounted on said operating member for rocking movement relative to said operating member to engage with and disengage from said roll,

a holding lever rockably mounted on said operating member for normally locking said pawl in a disengaging position from said roll, said holding lever being rocked by said key lever to release said pawl upon depression of said key lever,

said operating member being adapted to be moved from said rest position together with said pawl and holding lever by said roll when said pawl is released by said holding lever to engage with said roll thereby causing one of said type bars to strike toward the typing point,

a lateral frame located under said key levers and having a number of guide grooves equally spaced therein,

locking balls mounted on said lateral frame,

a fixed shaft secured to the lateral frame,

a bellcrank lever corresponding to each of said key levers and guided in said guide groove for rocking movement about the fixed shaft from an inoperative position in which one arm of said bellcrank lever is disengaged from said balls to an operative position in which one arm of said bellcrank lever is-engaged with said balls so as to prevent depression of more than one key lever simultaneously,

a leaf spring secured to said lateral frame and normally engaged with one arm of said bellcrank lever to positively maintain the bellcrank lever in the inoperative and operative positions respectively,

said lateral frame, said balls, said bellcrank lever, said fixed shaft and said leaf spring being secured to said frame as a unit,

said holding lever engaging another arm of said bellcrank lever for rocking the bellcrank lever from the inoperative position to the operative position when rocked upon depression of said key lever,

said another arm of said bellcrank lever being disposed in the fixed path of movement of the operating member when rocked into the operative position, and

a projection formed on the operating member for moving said another arm of the bellcrank lever out of the fixed path and restoring the bellcrank lever to the inoperative position after the initiation of the reciprocating movement of the operating member.

7. A power operated typewriter comprising:

a frame,

a power roll rotatably mounted on said frame,

key levers pivotally supported on said frame and depressible from a normal rest position,

type bars pivotally mounted on a type bar segment to strike at a common typing point,

an operating member connected to each of said type bars and mounted on said frame for reciprocating movement in a fixed path,

a spring mounted on said frame for normally urging said operating member to its normal rest position,

a pawl rockably mounted on said operating member for rocking movement relative to said operating member to engage with and disengage from said roll,

holding lever rockably mounted on said operating member for normally locking said pawl in a position disengaged from said roll, said holding lever being rocked by said key lever to release said pawl upon depression of said key lever,

said operating member being adapted to be moved from said rest position together with said pawl and holding lever by said roll when said pawl is released by said holding lever to engage with said roll, thereby causing one of said type bars to strike toward the typing point,

a lateral frame located under said key levers and having a number of guide grooves equally spaced therein,

locking balls mounted on said lateral frame,

a fixed shaft secured to the lateral frame,

a bellcrank lever corresponding to each of said key levers and guided in said guide groove for rocking movement about the fixed shaft from an inoperative position in which one arm of said bellcrank lever is disengaged from said balls to an operative position in which said one arm of said bellcrank lever is engaged with said balls so as to prevent depression of more than one key lever simultaneously,

a leaf spring secured to said lateral frame and normally engaged with one arm of said bellcrank lever to positively maintain the bellcrank lever in the inoperative and operative positions respectively,

said holding lever engaging another arm of said bellcrank lever for rocking the bellcrank lever from the inoperative position to the operative position when said holding lever is rocked upon depression of said key lever,

said another arm of said bellcrank lever being disposed in the fixed path of movement of the operating member when rocked into the operative position, and

a projection formed on the operating member for moving said another arm of the bellcrank lever from the fixed path and restoring the bellcrank lever to the inoperative position after the initiation of the reciprocating movement of the operating member. 

1. A power operated typewriter comprising: a frame, a drive member rotatably supported on said frame, key levers movably supported on said frame, type bars pivotably mounted on a type bar segment to strike at a common typing point, an operating member connected to each of said type bars and mounted on said frame for reciprocating movement in a fixed path, means for normally holding said operating member in a rest position, intermediate means carried by said operating member so as to engage with and disengage from said drive member, said intermediate means normally being held in said disengaging condition and adapted to move from said disengaging condition to said engaging condition upon depression of said key lever, thereby to initiate the reciprocating movement of said operating member, a lateral frame located under said key levers and having a number of guide grooves equally spaced therein, key locking members mounted on said lateral frame, a shaft secured to the lateral frame, a locking lever corresponding to each of said key levers and guided in said guide groove for pivotal movement about said shaft from an inoperative position in which said lever is disengaged from said locking members to an operative position in which said lever is engaged with said locking members, and spring means mounted on said lateral frame for engaging said locking lever to positively maintain it in said inoperative and operative positions, said lateral frame, said locking members, said locking lever, said shaft, and said spring means being secured to the frame as a unit, said intermediate means engaging said locking lever upon depression of said key lever for rocking the locking lever from the inoperative position to the operative position so as to prevent depression of more than one key lever simultaneously, said locking lever being disposed in the fixed path of movement of said operating member when rocked into the operative position, said operating member carrying said locking lever out of the fixed path and restoring the same to the inoperative position after the initiation of the reciprocating movement thereof.
 2. A power operated typewriter comprising: a frame including a lateral frame, a power roll rotatably mounted on said frame, key levers movably supported on said frame, type bars pivotally mounted on a type bar segment to strike at a common typing point, an operating member connected to each of said type bars and mounted on said frame for reciprocating movement in a fixed path, a spring mounted on the frame for normally urging said operating member to a rest position, intermediate means rockably mounted on the operating member for movement relative to the operating member so as to engage with and disengage from said roll, said intermediate means normally being in said disengaging condition and adapted to rock from said disengaging condition to said engaging condition upon depression of said key lever, thereby initiating the reciprocating movement of said operating member, key locking members located under said key levers and mounted on said lateral frame, a fixed shaft secured to the lateral frame, a bellcrank lever corresponding to each of said key levers and rockable about the fixed shaft from an inoperative position in which one arm of said lever is disengaged from said key locking members to an operative position in which said one arm of said lever is engaged with said key locking members, said intermediate means engaging another arm of said bellcrank lever upon depression of said key lever for rocking the bellcrank lever from the inoperative position to the operative position so as to prevent depression of more than one key lever simultaneously, said another arm of the bellcrank lever being disposed in the fixed path of movement of the operating member when said lever is rocked into the operative position, a leaf spring mounted on said lateral frame for contacting one arm of said bellcrank lever to positively maintain the bellcrank lever in said operative and inoperative positions respectively, and camming means on said operating member for engaging the locking lever so as to cam said another arm of the bellcrank lever out of said fixed path and restore the bellcrank lever to the inoperative position after the initiation of the reciprocating movement of the operating member.
 3. A power operated typewriter as claimed in claim 2, wherein said key locking members comprise a plurality of balls located in a groove formed in said lateral frame and arranged in a straight line, and wherein said lateral frame, said bellcrank levers, said balls, said fixed shaft and said leaf spring are secured, as a unit, to the frame.
 4. A power operated typewriter comprising: a frame, a power roll rotatably mounted on said frame, type bars pivotally mounted on a type bar segment to strike at a common typing point, an operating member connected to each of said type bars and mounted on said frame for reciprocating movement in a fixed path, a spring mounted on the frame for normally urging said operating member to a rest position, a pawl pivotally mounted on said operating member for rocking movement relative to said operating member to engage with and disengage from said roll, a holding lever rockably mounted on said operating member for normally locking said pawl in a position disengaged from said roll, said holding lever being rocked by said key lever to release said pawl upon depression of the key lever, said operating member being adapted to be moved from said rest position together with said pawl and holding lever by said roll when said pawl is released by the holding lever to engage with said roll, thereby causing one of said type bars to strike toward the typing point, key locking members located under the key levers and mounted on the frame, a locking lever corresponding to each of said key levers and rockably mounted on the frame for movement between an inoperative position in which said lever is disengaged from said key locking members and an operative position in which said lever is engaged with said key locking members, said holding lever engaging the locking lever for rocking the same from the inoperative position to the operative position when the holding lever is rocked upon depression of said key lever, said locking lever being disposed in the fixed path of movement of the operating member when rocked into the operative position, and camming means on the operating member for engaging the locking lever so as to move the locking lever out of the fixed path and restore it to the inoperative position after the initiation of the reciprocating movement of the operating member.
 5. A power operated typewriter comprising: a frame, a power roll rotatably mounted on said frame, key levers pivotally supported on said frame, type bars pivotally mounted on a type bar segment to strike at a common typing point, an operating member connected to each of said type bars and mounted on said frame for reciprocating movement in a fixed path, a spring mounted on said frame for normally urging said operating member to its normal rest position, a pawl rockably mounted on said operating member for rocking movement relative to said operating member to engage with and disengage from said roll, a holding lever rockably mounted on said operating member for normally locking said pawl in a position disengaged from said roll, said holding lever being rocked by said key lever to release said pawl upon depression of said key lever, said operating member being adapted to be moved from said rest position together with said pawl and said holding lever by said roll when said pawl is released by said holding lever to engage with said roll, thereby causing one of said type bars to strike toward said typing point, a lateral frame located under said key levers and having a number of guide grooves equally spaced therein, key locking members mounted on said lateral frame, a fixed shaft secured to the lateral frame, a bellcrank lever corresponding to each of said key levers and guided in said groove for rocking movement about the fixed shaft from an inoperative position in which one arm of said bellcrank lever is disengaged from said key locking members to an operative position in which one arm of said bellcrank lever is engaged with said key locking members so as to prevent depression of more than one key lever simultaneously, a spring mounted on said lateral frame for maintaining the bellcrank lever positively in said inoperative and operative positions, said lateral frame, said interlocking members, said bellcrank lever, said shaft and said spring being secured to said frame as a unit, said holding lever engaging another arm of the bellcrank lever for rocking the bellcrank lever from the inoperative position to the operative position when said holding lever is rocked upon depression of said key lever, said another arm of said bellcrank lever being disposed in the fixed path of movement of the operating member when rocked into the operative position, and a projection formed on the operating member for engaging said another arm of the bellcrank lever to move it out of the fixed path and restore the bellcrank lever to the inoperative position after the initiation of the reciprocating movement of the operating member.
 6. A power operated typewriter comprising: a frame, a power roll rotatably mounted on said frame, key levers pivotally supported on said frame and depressible from a normal rest position, type bars pivotally mounted on a type bar segment to strike at a common typing point, an operating member connected to each of said type bars and mounted on said frame for reciprocating movement in a fixed path, a spring mounted on said frame for normally urging said operating member to its normal rest position, a pawl rockably mounted on said operating member for rocking movement relative to said operating member to engage with and disengage from said roll, a holding lever rockably mounted on said operating member for normally locking said pawl in a disengaging position from said roll, said holding lever being rocked by said key lever to release said pawl upon depressIon of said key lever, said operating member being adapted to be moved from said rest position together with said pawl and holding lever by said roll when said pawl is released by said holding lever to engage with said roll thereby causing one of said type bars to strike toward the typing point, a lateral frame located under said key levers and having a number of guide grooves equally spaced therein, locking balls mounted on said lateral frame, a fixed shaft secured to the lateral frame, a bellcrank lever corresponding to each of said key levers and guided in said guide groove for rocking movement about the fixed shaft from an inoperative position in which one arm of said bellcrank lever is disengaged from said balls to an operative position in which one arm of said bellcrank lever is engaged with said balls so as to prevent depression of more than one key lever simultaneously, a leaf spring secured to said lateral frame and normally engaged with one arm of said bellcrank lever to positively maintain the bellcrank lever in the inoperative and operative positions respectively, said lateral frame, said balls, said bellcrank lever, said fixed shaft and said leaf spring being secured to said frame as a unit, said holding lever engaging another arm of said bellcrank lever for rocking the bellcrank lever from the inoperative position to the operative position when rocked upon depression of said key lever, said another arm of said bellcrank lever being disposed in the fixed path of movement of the operating member when rocked into the operative position, and a projection formed on the operating member for moving said another arm of the bellcrank lever out of the fixed path and restoring the bellcrank lever to the inoperative position after the initiation of the reciprocating movement of the operating member.
 7. A power operated typewriter comprising: a frame, a power roll rotatably mounted on said frame, key levers pivotally supported on said frame and depressible from a normal rest position, type bars pivotally mounted on a type bar segment to strike at a common typing point, an operating member connected to each of said type bars and mounted on said frame for reciprocating movement in a fixed path, a spring mounted on said frame for normally urging said operating member to its normal rest position, a pawl rockably mounted on said operating member for rocking movement relative to said operating member to engage with and disengage from said roll, a holding lever rockably mounted on said operating member for normally locking said pawl in a position disengaged from said roll, said holding lever being rocked by said key lever to release said pawl upon depression of said key lever, said operating member being adapted to be moved from said rest position together with said pawl and holding lever by said roll when said pawl is released by said holding lever to engage with said roll, thereby causing one of said type bars to strike toward the typing point, a lateral frame located under said key levers and having a number of guide grooves equally spaced therein, locking balls mounted on said lateral frame, a fixed shaft secured to the lateral frame, a bellcrank lever corresponding to each of said key levers and guided in said guide groove for rocking movement about the fixed shaft from an inoperative position in which one arm of said bellcrank lever is disengaged from said balls to an operative position in which said one arm of said bellcrank lever is engaged with said balls so as to prevent depression of more than one key lever simultaneously, a leaf spring secured to said lateral frame and normally engaged with one arm of said bellcrank lever to positively maintain the bellcrank lever in the inoperative and operative positions respectively, said holding lever engaging another arm of said bellcrank lever for rocking the bellcrank lever from the inoperative position to the operative position when said holding lever is rocked upon depression of said key lever, said another arm of said bellcrank lever being disposed in the fixed path of movement of the operating member when rocked into the operative position, and a projection formed on the operating member for moving said another arm of the bellcrank lever from the fixed path and restoring the bellcrank lever to the inoperative position after the initiation of the reciprocating movement of the operating member. 